U.S. patent application number 13/519002 was filed with the patent office on 2012-11-15 for hydrogel particles.
This patent application is currently assigned to KAO CORPORATION. Invention is credited to Kimikazu Fukuda, Kazuo Matsuyama, Koji Mine, Yuka Onishi.
Application Number | 20120288457 13/519002 |
Document ID | / |
Family ID | 44195228 |
Filed Date | 2012-11-15 |
United States Patent
Application |
20120288457 |
Kind Code |
A1 |
Onishi; Yuka ; et
al. |
November 15, 2012 |
HYDROGEL PARTICLES
Abstract
Hydrogel particles include: a continuous phase of
non-crosslinked hydrogel; and a dispersed phase dispersed in the
continuous phase. The dispersed phase includes a crystalline
organic UV absorber and a solid fat having an organic value (OV) of
310 or more and an inorganic value (IV) of 130 or more on an
organic conceptual diagram. The content of the crystalline organic
UV absorber in the dispersed phase is 15-70 mass %.
Inventors: |
Onishi; Yuka; (Wakayama-shi,
JP) ; Fukuda; Kimikazu; (Wakayama-shi, JP) ;
Matsuyama; Kazuo; (Wakayama-shi, JP) ; Mine;
Koji; (Wakayama-shi, JP) |
Assignee: |
KAO CORPORATION
Tokyo
JP
|
Family ID: |
44195228 |
Appl. No.: |
13/519002 |
Filed: |
December 16, 2010 |
PCT Filed: |
December 16, 2010 |
PCT NO: |
PCT/JP2010/007306 |
371 Date: |
June 25, 2012 |
Current U.S.
Class: |
424/60 ;
424/59 |
Current CPC
Class: |
A61K 8/062 20130101;
A61Q 17/04 20130101; A61K 8/042 20130101; B01J 13/0065
20130101 |
Class at
Publication: |
424/60 ;
424/59 |
International
Class: |
A61K 8/92 20060101
A61K008/92; A61Q 17/04 20060101 A61Q017/04; A61K 8/04 20060101
A61K008/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 2009 |
JP |
2009-293119 |
Claims
1-11. (canceled)
12. Hydrogel particles, comprising: a continuous phase of
non-crosslinked hydrogel; and a dispersed phase dispersed in the
continuous phase, wherein the dispersed phase comprises a
crystalline organic UV absorber and a solid fat having an organic
value of 310 or more and an inorganic value of 130 or more on an
organic conceptual diagram, and a content of the crystalline
organic UV absorber in the dispersed phase is 15-70 mass %.
13. The hydrogel particles of claim 12, wherein the solid fat has
an organic value of 310-1000 and an inorganic value of 130-800 on
the organic conceptual diagram.
14. The hydrogel particles of claim 12, wherein a ratio (IV)/(OV)
of the inorganic value (IV) to the organic value (OV) of the solid
fat on the organic conceptual diagram is 0.20-1.10.
15. The hydrogel particles of claim 12, wherein the crystalline
organic UV absorber has an organic value of 310-800 and an
inorganic value of 130-700 on the organic conceptual diagram.
16 The hydrogel particles of claim 12, wherein a ratio (IV)/(OV) of
the inorganic value (IV) to the organic value (OV) of the
crystalline organic UV absorber on the organic conceptual diagram
is 0.30-1.1.
17. The hydrogel particles of claim 12, wherein the solid fat is a
compound expressed by general formula (1):
R.sub.1COOCH.sub.2(CHX).sub.nCH.sub.2Y (1) wherein n is a number of
1-4, X and Yare independently represent H, OH, OCOR.sub.2, or
OCO(CH.sub.2).sub.2COOH, and R.sub.1 and R.sub.2 independently
represent linear saturated hydrocarbon groups each having 13-21
carbon atoms.
18. The hydrogel particles of claim 12, wherein the solid fat
comprises at least one of a glycerin fatty acid ester or an
alkylene glycol fatty acid ester.
19. The hydrogel particles of claim 12, wherein a total content of
the solid fat in the hydrogel particles is 0.2-30 mass %.
20. The hydrogel particles of claim 12, wherein a total content of
the crystalline organic UV absorber in the hydrogel particles is
3-50 mass %.
21. The hydrogel particles of claim 12, wherein a total content of
an oil component in the hydrogel particles is 0.01-60 mass %.
22. The hydrogel particles of claim 12, wherein a content of the
continuous phase in the hydrogel particles is 20-99 mass %.
23. The hydrogel particles of claim 12, wherein the continuous
phase comprises a gel-forming agent and water.
24. The hydrogel particles of claim 12, wherein a content of the
dispersed phase in the hydrogel particles is 1-70 mass %.
25. The hydrogel particles of claim 12, wherein a content of the
solid fat in the dispersed phase is 1-85 mass %.
26. The hydrogel particles of claim 12, wherein a content ratio of
the crystalline organic UV absorber to the solid fat in the
dispersed phase (a content of the crystalline organic UV absorber
in the dispersed phase/a content of the solid fat in the dispersed
phase) is 0.1-50.
27. The hydrogel particles of claim 12, wherein the crystalline
organic UV absorber is diethylamino hydroxybenzoyl hexyl benzoate,
dimethoxybenzylidene dioxoimidazolidine propionate octyl, or
t-butyl methoxybenzoyl methane.
28. An UV-shielding cosmetic product comprising the hydrogel
particles of claim 12.
29. The UV-shielding cosmetic product of claim 28, wherein a
content of the hydrogel particles in an UV-shielding cosmetic
product is 5-80 mass %.
30. A method for producing hydrogel particles in which a dispersed
phase comprising a crystalline organic UV absorber and a solid fat
having an organic value of 310 or more and an inorganic value of
130 or more on an organic conceptual diagram is dispersed in a
continuous phase of non-crosslinked hydrogel comprising a
gel-forming agent and water, by dropping, spraying, or stirring a
mixture comprising the crystalline organic UV absorber, the solid
fat, the gel-forming agent, and the water, wherein the mixture is
prepared such that a content of the crystalline organic UV absorber
in the dispersed phase in the hydrogel particles is 15-70 mass
%.
31. The method of claim 30, wherein the mixture is prepared by
mixing at a gelation temperature of the gel-forming agent or
higher.
32. The method of claim 31, wherein the mixture is prepared by
mixing a mixture A comprising the gel-forming agent and water and a
mixture B comprising the crystalline organic UV absorber and the
solid fat at the gelation temperature of the gel-forming agent or
higher.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to hydrogel particles and
methods for producing hydrogel particles.
BACKGROUND ART
[0002] Application of hydrogel particles including oil components
has been examined in the fields of cosmetics, drugs, quasi drugs,
and the like (see, for example, Patent Document 1). Patent Document
2 shows a skin cosmetic product in which hydrogel particles
including an oil component are dispersed in an aqueous solvent.
CITATION LIST
Patent Document
[0003] [Patent Document 1] Japanese Patent Publication No.
2002-159838
[0004] [Patent Document 2] Japanese Patent Publication No.
2002-20227
SUMMARY OF THE INVENTION
[0005] The present disclosure is directed to hydrogel particles
including: a continuous phase of non-crosslinked hydrogel; and a
dispersed phase dispersed in the continuous phase, wherein the
dispersed phase includes a crystalline organic UV absorber and a
solid fat having an organic value of 310 or more and an inorganic
value of 130 or more on an organic conceptual diagram, and a
content of the crystalline organic UV absorber in the dispersed
phase is 15-70 mass %.
[0006] The present disclosure is also directed to a method for
producing hydrogel particles in which a dispersed phase including a
crystalline organic UV absorber and a solid fat having an organic
value of 310 or more and an inorganic value of 130 or more on an
organic conceptual diagram is dispersed in a continuous phase of
non-crosslinked hydrogel including a gel-forming agent and water,
by dropping, spraying, or stirring a mixture including the
crystalline organic UV absorber, the solid fat, the gel-forming
agent, and the water, wherein the mixture is prepared such that a
content of the crystalline organic UV absorber in the dispersed
phase in the hydrogel particles is 15-70 mass %.
[0007] The present disclosure is also directed to an UV-shielding
cosmetic product containing the hydrogel particles of the present
disclosure.
DESCRIPTION OF EMBODIMENTS
[0008] An embodiment will be described in detail hereinafter.
Hydrogel Particles
[0009] Hydrogel particles according to this embodiment are to be
included in, for example, cosmetics, drugs, quasi drugs, and
include a continuous phase of non-crosslinked hydrogel and a
dispersed phase dispersed in the continuous phase. The dispersed
phase includes a crystalline organic ultraviolet radiation (UV)
absorber and a solid fat having an organic value (OV) of 310 or
more and an inorganic value (IV) of 130 or more on an organic
conceptual diagram. The content of the crystalline organic UV
absorber in the dispersed phase is 15-70 mass %.
[0010] The crystalline organic UV absorber is included in, for
example, cosmetics, but has low solubility in various types of oils
and solvents commonly used in cosmetics. Thus, it is difficult to
incorporate the crystalline organic UV absorber in cosmetics with
stability.
[0011] Incorporating the crystalline organic UV absorber in the
hydrogel particles has problems such as a low degree of flexibility
in prescription and deterioration of UV absorption ability for the
following reasons. For example, the crystalline organic UV absorber
is not easily dissolved in oil components. In addition, when the
crystalline organic UV absorber is dissolved in an oil component,
crystal is easily precipitated in a solution in a storage
period.
[0012] With the hydrogel particles of this embodiment, however, the
foregoing composition can reduce crystal precipitation of the
crystalline organic UV absorber in a storage period regardless of a
high concentration of 15-70 mass % of the crystalline organic UV
absorber in the dispersed phase.
[0013] The "hydrogel particles" herein means one or a plurality of
particles in which a dispersed phase is dispersed in a continuous
phase of non-crosslinked hydrogel, excluding a capsule composed of
an inner layer, i.e., a core, and an outer layer, i.e., a shell,
which are concentrically disposed. The "hydrogel" herein is a gel
obtained from a gel-forming agent using water as a solvent. The
structure in which the dispersed phase is dispersed in the
continuous phase in the hydrogel particles can be observed by, for
example, photography analysis with a freeze-fracture SEM.
[0014] From the viewpoints of appearance and productivity, the
volume-based average particle size of the hydrogel particles is
preferably 10-10000 .mu.m, more preferably 10-5000 .mu.m, much more
preferably 30-3000 .mu.m, still much more preferably 60-500 .mu.m,
and especially preferably 60-250 .mu.m. The volume-based average
particle size of the hydrogel particles can be measured with a
laser diffraction/scattering method (e.g., LA-920 manufactured by
HORIBA, Ltd.) or a sieve method. To measure particles with a
particle size of 1000 .mu.m or less, the laser
diffraction/scattering method is preferably employed. To measure
particles with a particle size exceeding 1000 .mu.m, the sieve
method is preferably employed.
[0015] The shape of the hydrogel particles is not specifically
limited, and is preferably the shape of a body of revolution
composed of a curved surface. The "body of revolution composed of a
curved surface" herein means a shape defined by revolving a closed
plane formed by a virtual axis and a continuous curve round on the
virtual axis, and does not include shapes having flat surfaces such
as triangular pyramids and cylinders. The shape of the hydrogel
particles is more preferably spherical or oval from the viewpoint
of aesthetic appearance.
Continuous Phase
[0016] The continuous phase is made of non-crosslinked hydrogel as
an aqueous component, and includes a gel-forming agent and
water.
[0017] The content of the continuous phase in the hydrogel
particles is preferably 20-99 mass %, more preferably 25-85 mass %,
and much more preferably 30-80 mass %, from the viewpoint of
prevention of fracture in cleaning the hydrogel particles and
incorporating the hydrogel particles in cosmetics or other
products.
[0018] The "non-crosslinked hydrogel" herein means a product of
gelation caused by the heat-reversibility of sol-gel. The
dissolution temperature of the non-crosslinked hydrogel in water is
preferably 75.degree. C. or more in general and more preferably
75-90.degree. C. The gelation temperature of the non-crosslinked
hydrogel when cooled after dissolution in water is preferably
30-45.degree. C.
[0019] The jelly strength of the non-crosslinked hydrogel is
preferably 147 kPa (1500 g/cm.sup.2) or less, and more preferably
19.6 kPa (200 g/cm.sup.2) to 127 kPa (1300 g/cm.sup.2) from the
viewpoint of the feel of cosmetics or other products containing the
hydrogel particles when used. The jelly strength can be obtained
with a Nikkansuishiki method in the following manner. Specifically,
first, a 1.5 mass % aqueous solution of a gel-forming agent is
prepared, and is allowed to stand at 20.degree. C. for 15 hours to
obtain a gel product. Then, a load is applied to the gel using a
Nikkansuishiki jelly strength measuring apparatus (manufactured by
Kiya-seisakusho Co., Ltd.). The jelly strength is obtained as the
maximum mass (g) per a unit surface area of 1 cm.sup.2 when the gel
withstands the load for 20 seconds at 20.degree. C.
Gel-Forming Agent
[0020] Examples of the gel-forming agent include agar, carrageenan,
and gelatin. Among these materials, agar is preferable. The
gel-forming may be made of a single species or a plurality of
species.
[0021] The content of the gel-forming agent in the continuous phase
is 0.1 mass % or more, more preferably 0.3 mass % or more, much
more preferably 0.4 mass % or more, and especially preferably 0.5
mass % or more, from the viewpoints of enhancing the feel of
cosmetics or other products containing the hydrogel particles when
used and preventing fracture in cleaning the hydrogel particles and
incorporating the hydrogel particles in cosmetics or other
products. The content of the gel-forming agent in the hydrogel
particles is preferably 8.0 mass % or less, more preferably 7.0
mass % or less, much more preferably 6.0 mass % or less, and
especially preferably 5.0 mass % or less, from the viewpoints of
enhancing the feel of cosmetics or other products containing the
hydrogel particles when used and preventing fracture in cleaning
the hydrogel particles and incorporating the hydrogel particles in
cosmetics or other products.
Dispersed Phase
[0022] The dispersed phase includes an oil component containing a
solid fat and also includes a crystalline organic UV absorber.
[0023] The content of the dispersed phase in the hydrogel particles
is preferably 1-70 mass %, more preferably 7.5-70 mass %, much more
preferably 10-70 mass %, still much more preferably 15-60 mass %,
and especially preferably 20-50 mass %, from the viewpoint of
prevention of fracture in cleaning the hydrogel particles and
incorporating the hydrogel particles in cosmetics or other
products.
[0024] The volume-based average particle size of the dispersed
phase is preferably 1/10 or less of the volume-based average
particle size of the hydrogel particles. Specifically, the
volume-based average particle size of the dispersed phase is
preferably 0.01-100 .mu.m, more preferably 0.5-50 .mu.m, and much
more preferably 0.5-20 .mu.m, from the viewpoints of smooth
spreadability over the skin of cosmetics or other products
containing the hydrogel particles, prevention of leakage of the
dispersed phase from the hydrogel particles, compatibility with the
skin of cosmetics or other products containing the hydrogel
particles. The volume-based average particle size of the dispersed
phase in the state of a dispersion before formation of particles
can be measured with a laser diffraction/scattering method using a
laser diffraction/scattering particle size distribution analyzer
(e.g., LA-920 manufactured by HORIBA, Ltd.).
Oil Component
[0025] The oil component includes a solid fat, but may be made only
of a solid fat or may also include liquid oil. The "solid fat"
herein is an oil component having a melting point of 35.degree. C.
or more. The "liquid oil" herein is an oil component having a
melting point less than 35.degree. C. The melting points of solid
fat and liquid oil can be measured by differential scanning
calorimetry (DSC).
[0026] The content of the oil component in the dispersed phase is
preferably 30-85 mass %, more preferably 30-80 mass %, much more
preferably 30-65 mass %, and especially preferably 40-60 mass %,
from the viewpoint of enhancing the feel of cosmetics or other
products containing the hydrogel particles when used. The total
content of the oil component in the hydrogel particles is
preferably 0.01-60 mass %, more preferably 3.0-50 mass %, much more
preferably 5.0-40 mass %, and especially preferably 7.5-25 mass %,
from the viewpoints of enhancing the feel of cosmetics or other
products containing the hydrogel particles when used and preventing
fracture in cleaning the hydrogel particles and incorporating the
hydrogel particles in cosmetics or other products.
[0027] The melting point of the oil component is preferably
35.degree. C. or more, more preferably 40-90.degree. C., and much
more preferably 40-80.degree. C., from the viewpoint of preventing
leakage of the oil component from the hydrogel particles during
storage at high temperatures. The melting point of the oil
component can also be measured by differential scanning
calorimetry.
Solid Fat
[0028] The solid fat includes a solid fat having an organic value
(OV) of 310 or more and an inorganic value (IV) of 130 or more on
an organic conceptual diagram (hereinafter referred to as a "solid
fat A").
[0029] The "organic conceptual diagram" herein is a diagram in
which the degree of covalent bond of a compound is evaluated as an
organic value (OV) and the degree of ionic bond is evaluated as an
inorganic value (IV) and location of a compound is plotted as
points (OV, IV) on a plane of rectangular coordinates with the
abscissa used as an organic axis and the ordinate used as an
inorganic axis. The organic value (OV) is obtained by multiplying
the carbon number of the component by 20. The inorganic value (IV)
is a cumulative sum of inorganic values provided to substituents
included in the compound. With respect to inorganic values, see a
table on page 13 in "Organic Conceptual Diagram--basis and
application--" (Yoshio KODA, Sankyo Publishing, 1984).
[0030] The solid fat A has an organic value (OV) of 310 or more.
The organic value (OV) of the solid fat A is preferably 330 or
more, more preferably 350 or more, and much more preferably 400 or
more. In addition, the organic value (OV) of the solid fat A is
preferably 1000 or less and more preferably 800 or less. The solid
fat A has an inorganic value (IV) of 130 or more. The inorganic
value (IV) of the solid fat A is preferably 140 or more and more
preferably 150 or more. In addition, the inorganic value (IV) of
the solid fat A is preferably 800 or less, more preferably 700 or
less, and much more preferably 500 or less.
[0031] As the inorganic value (IV)/organic value (OV)=IOB value,
the solid fat A preferably has 0.20.ltoreq.IOB value.ltoreq.1.10
and more preferably 0.25.ltoreq.IOB value.ltoreq.1.00. As the JOB
value.times.10=HLB value, the solid fat A preferably has
2.03.ltoreq.HLB value.ltoreq.11.0 and more preferably
2.5.ltoreq.HLB value.ltoreq.10.0. The angle a formed by the organic
axis and the line passing through the origin and points (OV, IV) of
the solid fat A on the organic conceptual diagram is preferably
11.degree..ltoreq..alpha..ltoreq.48.degree., more preferably
13.degree..ltoreq..alpha..ltoreq.48.degree., and much more
preferably 15.degree..ltoreq..alpha..ltoreq.47.degree..
[0032] Examples of the solid fat A include glycerin fatty acid
esters, alkylene glycol fatty acid esters, and solid ceramide.
[0033] Examples of glycerin fatty acid esters include stearic acid
monoglyceride (OV=420, IV=260, IOB value=0.62, HLB value=6.2),
behenic acid monoglyceride (OV=500, IV=260, JOB value=0.52, HLB
value=5.2), stearic acid monoglyceride succinate (OV=500, IV=380,
IOB value=0.76, HLB value=7.6), stearic acid diglyceride (OV=780,
IV=220, IOB value=0.28, HLB value=2.8), and behenic acid
diglyceride (OV=860, IV=220, JOB value=0.26, HLB value=2.6).
[0034] Examples of alkylene glycol fatty acid esters include
propylene glycol monostearate (OV=420, IV=160, IOB value=0.38, HLB
value=3.8), and propylene glycol monobehenate (OV=500, IV=160, IOB
value=0.32, HLB value=3.2).
[0035] Examples of solid ceramide include
N-(2-hydroxy-3-hexadecyloxypropyl)-N-2-hydroxyethylhexadecanamide
(OV=780, IV=355, IOB value=0.46, HLB value=4.6).
[0036] Among the above-mentioned types of the solid fat A, glycerin
fatty acid esters and alkylene glycol fatty acid esters are
preferable.
[0037] The solid fat A is preferably a compound expressed by the
following general formula (1):
R.sub.1COOCH.sub.2(CHX).sub.nCH.sub.2Y (1)
(wherein n is a number of 1-4, X and Y independently represent H,
OH, OCOR.sub.2, or OCO(CH.sub.2).sub.2COOH, and R.sub.1 and R.sub.2
independently represent linear saturated hydrocarbon groups each
having 13-21 carbon atoms).
[0038] In the general formula (1), n is preferably 1-2, and more
preferably 1 (one). In addition, X is more preferably H, OH, or
OCOR.sub.2. Further, Y is more preferably OH, OCOR.sub.2, or
OCO(CH.sub.2).sub.2COOH.
[0039] The solid fat A may include a single species or a plurality
of species.
[0040] The content of the solid fat A in the dispersed phase is
preferably 1-85 mass %, more preferably 1-75 mass %, much more
preferably 3-70 mass %, and still much more preferably 5-60 mass %,
from the viewpoints of incorporating a large amount of a
crystalline organic UV absorber with stability, preventing leakage
of the oil component from the hydrogel particles, and easily
spreading cosmetics or other projects containing the hydrogel
particles over the skin. The total content of the solid fat A in
the hydrogel particles is preferably 0.2-30 mass % and more
preferably 1.0-20 mass %.
[0041] The melting point of the solid fat A is 35.degree. C. or
more, and is preferably 40-120.degree. C. and more preferably
40.degree. C.-80.degree. C. from the viewpoint of preventing
leakage of the oil component from the hydrogel particles.
[0042] The oil component may include only the solid fat A as a
solid fat, or may include another solid fat in addition to the
solid fat A as long as reduction of crystal precipitation by the
high-concentration crystalline organic UV absorber is not
inhibited. Examples of the solid fat included in addition to the
solid fat A include solid paraffin and higher alcohol.
Liquid Oil
[0043] Examples of liquid oil include liquid skin-protecting
agents, liquid UV absorbers, liquid oil products, and liquid
perfume.
[0044] Examples of the liquid skin-protecting agents include:
liquid fats and oils such as liquid paraffin, liquid ester oils,
liquid higher alcohols, liquid squalanes, and liquid glycerides;
and liquid ceramides such as cetyloxypropyl glyceryl methoxypropyl
myristamide.
[0045] Examples of the liquid UV absorbers include p-aminobenzoic
acid, methyl p-aminobenzoate, glyceryl p-aminobenzoate,
p-dimethylaminoamyl bezoate, p-dimethylaminooctyl bezoate, ethylene
glycol salicylate, phenyl salicylate, octyl salicylate, butylphenyl
salicylate, homomentyl salicylate, octyl p-methoxy cinnamate,
ethoxyethyl methoxy cinnamate, glyceryl monoethylhexanoyl dimethoxy
cinnamate, hydroxymethoxy benzophenone, dihydroxydimethoxy
benzophenone, and octyltriazone.
[0046] Examples of the liquid oil products include: liquid
hydrocarbon oil; liquid vegetable oil; liquid fatty acids; liquid
fats and oils such as liquid ethylene glycol difatty acid ester (in
which a carbon number of fatty acid is 12-36 and which is a
branched saturated or unsaturated hydrocarbon group), liquid
dialkyl ester (in which the carbon number of fatty acid is 12-36
and which is a branched saturated or unsaturated hydrocarbon
group); and liquid silicones.
[0047] The liquid oil may include a single species or a plurality
of species.
[0048] The content of the liquid oil in the dispersed phase is
preferably 0-75 mass %, more preferably 0-65 mass %, much more
preferably 0-60 mass %, and still much more preferably 0-50 mass %,
from the viewpoints of incorporating a large amount of the
crystalline organic UV absorber having a low degree of solubility
with stability and spreadability over the skin of cosmetics or
other products containing the hydrogel particles. The total content
of the liquid oil in the hydrogel particles is preferably 0-25 mass
% and more preferably 0-20 mass %.
Crystalline Organic UV Absorber
[0049] The term "crystalline" herein means that a peak and a
crystalline state can be observed by X-ray diffraction. The
"organic UV absorber" herein means a compound having a property of
absorbing ultraviolet radiation whose wavelength range is 280-400
nm, especially UVA whose wavelength range is 320-400 nm, and
including no inorganic substances such as titanium and zinc. The
presence/absence of the UV absorption property can be detected by
using, for example, an SPF analyzer.
[0050] Examples of the crystalline organic UV absorber include
diethylamino hydroxybenzoyl hexyl benzoate (OV=480, IV=325, IOB
value=0.68, HLB value=6.77), dimethoxybenzylidene
dioxoimidazolidine propionate octyl (OV=460, IV=462, IOB
value=1.00, HLB value=10.04), and t-butyl methoxybenzoyl methane
(OV=380, IV=180, IOB value=0.47, HLB value=4.74). The crystalline
organic UV absorber may include a single species or a plurality of
species.
[0051] The organic value (OV) of the crystalline organic UV
absorber is preferably 310-800, more preferably 330-700, and much
more preferably 350-600. The inorganic value (IV) of the
crystalline organic UV absorber is preferably 130-700 and more
preferably 150-600.
[0052] The crystalline organic UV absorber preferably has
0.30.ltoreq.IOB value.ltoreq.1.1 and more preferably
0.35.ltoreq.IOB value.ltoreq.1.00. The crystalline organic UV
absorber preferably has 3.0.ltoreq.HLB value.ltoreq.11 and more
preferably 3.5.ltoreq.HLB value.ltoreq.10.0. The crystalline
organic UV absorber preferably has
16.degree..ltoreq..alpha..ltoreq.48.degree., more preferably
18.degree..ltoreq..alpha..ltoreq.48.degree., and much more
preferably 21.degree..ltoreq..alpha..ltoreq.47.degree. where
.alpha. is an angle formed by an organic axis and a line passing
through the origin and a point (OV, IV) on the organic conceptual
diagram.
[0053] The organic value (OV) of the crystalline organic UV
absorber is preferably within .+-.250, more preferably within
.+-.200, much more preferably within .+-.150, and especially
preferably within .+-.100, of the organic value (OV) of the solid
fat A. The inorganic value (IV) of the crystalline organic UV
absorber is preferably within .+-.350, more preferably within
.+-.300, much more preferably within .+-.200, still much more
preferably within .+-.150, and especially preferably within
.+-.100, of the inorganic value (IV) of the solid fat A.
[0054] The content of the crystalline organic UV absorber in the
dispersed phase is 15-70 mass %, and from the viewpoint of UV
protection, preferably 20-70 mass % and more preferably 40-70 mass
%. The content ratio of the crystalline organic UV absorber to the
solid fat A in the dispersed phase (i.e., the content of the
crystalline organic UV absorber in the dispersed phase/the content
of the solid fat A in the dispersed phase) is preferably 0.1-50,
more preferably 0.15-30, and more preferably 0.2-15. The total
content of the crystalline organic UV absorber in the hydrogel
particles is preferably 3-50 mass %, more preferably 5-40 mass %,
and much more preferably 10-30 mass %, from the viewpoint of UV
protection.
Optional Components
[0055] The continuous phase may include a water-soluble organic
compound such as sugars, polyhydric alcohol, a water-soluble
polymer compound, and water-soluble perfume described in Japanese
Patent Publication No. 2000-126586, in addition to the gel-forming
agent of non-crosslinked hydrogel and water.
[0056] Each of the continuous phase and the dispersed phase may
include a component such as an emulsifying/dispersing agent, which
will be described later, a coloring agent, or a preservative.
Examples of the coloring agent include pigments and dyes. Examples
of the pigments include inorganic pigments such as carbon black,
iron red, and titanium oxide, and organic pigments such as tar dye.
Examples of the dyes include oil-soluble dyes, vat dyes, and lake
dyes. Examples of the preservatives include methyl
p-hydroxybenzoate, isopropylmethylphenol, dehydroacetic acid, and
salts thereof.
[0057] Each of the continuous phase and the dispersed phase may
include components such as humectants, antiperspirants,
antibacterial agents, bactericides, and powders, which are
applicable to cosmetics, drugs, quasi drugs, and the like.
Method For Producing Hydrogel Particles
[0058] Now, a method for producing hydrogel particles according to
this embodiment will be described.
Preparation of Oil-In-Water Dispersion
[0059] First, a solution mixture A is prepared by mixing an aqueous
component of a gel-forming agent and ion-exchanged water as a
continuous phase component solution and heating the solution
mixture at its dissolution temperature or higher so that the
component is sufficiently dissolved therein. On the other hand, a
solution mixture B is prepared by mixing an oil component and a
crystalline organic UV absorber as a dispersed phase component
solution with heat so that the components are sufficiently
dissolved therein. In this process, the dispersed phase component
solution is prepared such that the content of the crystalline
organic UV absorber in the dispersed phase of final hydrogel
particles is 15-70 mass %.
[0060] Then, the continuous phase component solution (i.e., the
solution mixture A) and the dispersed phase component solution
(i.e., the solution mixture B) are mixed together at a gelation
temperature or higher, thereby preparing an oil-in-water dispersion
(mixture). In this process, the method for preparing the
oil-in-water dispersion is not specifically limited, and any known
technique using various types of agitators, dispersers, or the like
may be employed. The oil-in-water dispersion is prepared such that
the content of the crystalline organic UV absorber in the dispersed
phase of final hydrogel particles is 15-70 mass %.
[0061] From the viewpoint of stability of the oil-in-water
dispersion, before or after mixing of the continuous phase
component solution and the dispersed phase component solution, an
emulsifying/dispersing agent is preferably added to the continuous
phase component solution and/or the dispersed phase component
solution before the mixing or the solution mixture thereof after
the mixing. Among these cases, it is more preferable to add the
emulsifying/dispersing agent to the continuous phase component
solution before the mixing.
[0062] Examples of the emulsifying/dispersing agent include polymer
emulsifying/dispersing agents, nonionic surfactants, anionic
surfactants, cationic surfactants, and amphoteric surfactants. A
single species of the emulsifying/dispersing agent may be added, or
a plurality of species of the emulsifying/dispersing agents may be
added.
[0063] Among the above-listed emulsifying/dispersing agents, from
the viewpoints of spreadability over the skin of cosmetics or other
products containing the hydrogel particles and excellent handling
in cleaning the hydrogel particles and incorporating the hydrogel
particles in cosmetics or other products, the nonionic surfactant,
the anionic surfactant, the cationic surfactant, a combination of
the amphoteric surfactant and the polymer emulsifying/dispersing
agent, or a combination of the nonionic surfactant and the polymer
emulsifying/dispersing agent is preferably used, or the polymer
emulsifying/dispersing agent is preferably used alone. In the case
of using the polymer emulsifying/dispersing agent as the
emulsifying/dispersing agent, addition of the surfactant can be
reduced or eliminated, leading to reduction of greasiness by the
surfactant when cosmetics or other products containing the hydrogel
particles are applied onto the skin.
[0064] Examples of the polymer emulsifying/dispersing agent include
acrylate-alkyl methacrylate copolymer, a complex synthesized from
an amphoteric polymer compound and a higher fatty acid described in
Japanese Patent Publication No. H07-100356, water-soluble
amphiphilic polymer electrolytes described in Japanese Patent
Publications Nos. H08-252447 and H09-141079, water-soluble
crosslinked amphiphilic polymer electrolytes described in Japanese
Patent Publications Nos. H09-141080 and H09-141081, acrylic acid
copolymer described in Japanese Patent Publication No. H10-53625,
polysaccharide derivatives described in Japanese Patent No. 3329689
and Japanese Patent Publications Nos. H10-330401 and H11-106401,
synthetic polymer compounds such as polyvinylpyrrolidone, polyvinyl
alcohol, and derivatives thereof, polyacrylamide, and ethylene
oxide adducts of alkylphenol-formaldehyde condensation products,
and natural polymer compounds such as guar gum, karaya gum,
tragacanth gum, gum arabic, arabinogalactan, and casein.
[0065] Among the above polymer emulsifying/dispersing agents, from
the viewpoint of reduction of greasiness of cosmetics or other
products containing the hydrogel particles when applied onto the
skin, an acrylate-alkyl methacrylate copolymer (e.g., Nikko
Chemicals Co., Ltd., product name: PEMULEN), polyvinyl alcohol
(e.g., Nippon Synthetic Chemical Industry Co., Ltd., product name:
GOHSENOL), and a polysaccharide derivative described in Japanese
Patent No. 3329689 are preferably used.
[0066] From the viewpoint of improvement of femulsifiability and
dispersibility, a neutralized polymer emulsifying/dispersing agent
may be added. Alternatively, a pH adjuster such as potassium
hydroxide and sodium hydroxide may be added after the addition so
as to neutralize the polymer emulsifying/dispersing agent. The pH
after neutralization is preferably 4-8 and more preferably 6-7.
[0067] Examples of the anionic surfactants include sodium lauryl
sulfate, sodium stearate, and polyoxyethylene lauryl ether sodium
phosphate.
[0068] Examples of the cationic surfactants include lauryl
trimethyl ammonium chloride, stearylamine acetate, and stearylamine
acid.
[0069] From the viewpoint of prevention of leakage of the oil
component from the final hydrogel particles, the nonionic
surfactant having an HLB value of 10 or less is preferably used,
the nonionic surfactant having an HLB value of 8 or less is more
preferably used, the nonionic surfactant having an HLB value of 5
or less is much more preferably used, and the nonionic surfactant
having an HLB value of 3 or less is especially preferably used. The
HLB value can be determined based on a formula described in
"Techniques of Emulsification and Solubilization" published by
Kougakutosho Ltd. (May 20, 1984), pp. 8-12.
[0070] Among the nonionic surfactants mentioned above, from the
viewpoint of less skin irritation cased by cosmetics or other
products containing the final hydrogel particles, sorbitan fatty
acid esters, polyoxyethylene sorbitan fatty acid esters, and
polyoxyethylene sorbitol fatty acid esters are preferably used, and
sorbitan monostearate is more preferably used. From the viewpoint
of prevention of leakage of the oil component from the final
hydrogel particles, the nonionic surfactant having a melting point
of 35.degree. C. or more is preferably used, the nonionic
surfactant having a melting point of 40-90.degree. C. is more
preferably used, the nonionic surfactant having a melting point of
50-90.degree. C. is much more preferably used, and the nonionic
surfactant having a melting point of 60-80.degree. C. is especially
preferably used.
[0071] Examples of the amphoteric surfactants include
alkydimethylaminoacetic acid betaine and lecithin.
Particle Formation of Oil-In-Water Dispersion
[0072] Then, after preparation of the oil-in-water dispersion,
hydrogel particles are produced from the oil-in-water dispersion
with a commonly-employed dropping, spraying, or stirring technique.
From the viewpoint of prevention of leakage of the oil component
from the hydrogel particles, the dropping technique and the
spraying technique are more preferable than the stirring
technique.
[0073] In the dropping technique, the oil-in-water dispersion is
discharged through holes and, utilizing properties of the
oil-in-water dispersion of changing into droplets due to its
surface or interfacial tension, these droplets are solidified by
cooling in a gas phase such as air or a liquid phase to form
hydrogel particles. From the viewpoint of forming hydrogel
particles with a uniform particle size, vibration is preferably
applied to the oil-in-water dispersion which is being discharged
through holes.
[0074] In the spraying technique, a spray nozzle is used to spray a
dispersion therefrom, droplets are formed by utilizing the surface
tension of the dispersion, and these droplets are solidified by
cooling the droplets in a gas phase to form hydrogel particles.
[0075] In the stirring technique, the oil-in-water dispersion is
added to a solution which has the property of not being
substantially mixed with the oil-in-water dispersion and is
adjusted at a gelation temperature or higher, then shearing force
by stirring is applied to the resultant solution to change the
oil-in-water dispersion into fine particles, and utilizing the
property of changing into droplets by the interfacial tension,
these droplets are solidified by cooling in the solution which is
not substantially mixed with the oil-in-water dispersion, thereby
producing hydrogel particles.
[0076] In each of these dropping, spraying, and stirring
techniques, the temperature of the oil-in-water dispersion at
discharge, spraying, or addition is preferably in the range from a
gelation temperature to 100.degree. C., both inclusive. From the
viewpoint of easily producing aesthetic spherical particles, the
oil-in-water dispersion is preferably at a temperature +10.degree.
C. higher than the gelation temperature or more and more preferably
at a temperature +20.degree. C. higher than the gelation
temperature or more. The upper limit of the temperature of the
oil-in-water dispersion is 100.degree. C., which is the boiling
point of water.
[0077] The size of the hydrogel particles obtained in the manner
described above may be further reduced by pulverization or other
processes, as necessary.
UV-Shielding Cosmetic Product
[0078] An UV-shielding cosmetic product having an UV-shielding
property can be obtained by incorporating the hydrogel particles.
In this case, the hydrogel particles are applicable to both w/o and
o/w type cosmetic products. In particular, the o/w type cosmetic
products are preferable.
[0079] The content of the hydrogel particles in an UV-shielding
cosmetic product is preferably 5-80 mass %, more preferably 5-75
mass %, and much more preferably 5-50 mass %.
[0080] The UV absorbing effect of the UV-shielding cosmetic product
can be enhanced by further including an organic UV absorber. The
organic UV absorber is not specifically limited, and any one of an
oil-soluble organic UV absorber or a water-soluble organic UV
absorber may be used. For example, the organic UV absorber
described in Japanese Patent Publication No. 2006-225311 may be
used. Examples of the oil-soluble organic UV absorber include those
based on benzoic acid, salicylic acid, cinnamic acid, benzophenone,
benzoylmethane, triazine, and bonzotriazine.
[0081] The total content of the organic UV absorber in the
UV-shielding cosmetic product is preferably 1-35 mass %, more
preferably 5-30 mass %, and much more preferably 8-25 mass %, from
the viewpoints of reduction of stickiness on the skin and the UV
absorbing effect.
[0082] From the viewpoint of adjusting the feel, the UV-shielding
cosmetic product may contain an oil product. Examples of the oil
product include the oil product described in Japanese Patent
Publication No. 2006-225311. Among the examples, ester oil and
silicone oil are especially preferable in terms of improvement of
the feel. The content of the oil product in the UV-shielding
cosmetic product is preferably 0.1-15 mass % and more preferably
0.1-10 mass %.
[0083] The UV-shielding cosmetic product may include a surfactant
(excluding a polymer emulsifying/dispersing agent) from the
viewpoint of enhancement of stability of the cosmetic product.
Examples of the surfactant include nonionic surfactants, anionic
surfactants, cationic surfactants, and amphoteric surfactants as
described above. The content of the surfactant (excluding the
surfactant present in the hydrogel particles) in the UV-shielding
cosmetic product is preferably 5 mass % or less, more preferably 3
mass % or less, and much more preferably 1 mass % or less, from the
viewpoint of obtaining an excellent feeling on the skin.
[0084] In addition to the ingredients mentioned above, the
UV-shielding cosmetic product may contain a polymer
emulsifying/dispersing agent, a skin whitening agent, a
bactericide, an antiperspirant, a humectant, a cooling agent,
perfume, and/or a coloring agent, for example, as long as
advantages of the present disclosure are not impaired.
[0085] Application of the above UV-shielding cosmetic product onto
the skin can reduce stickiness or dryness of the skin, and
moreover, these feels are sustained so that effective ingredients
of, for example, the UV absorber can remain on the skin for a long
time.
EXAMPLES
Test Evaluationl
[0086] (Hydrogel particles)
[0087] Hydrogel particles of Examples 1-9 and Comparative Examples
1-5 were produced in the following manner. Compositions of the
hydrogel particles are also shown in Tables 1 and 2.
Example 1
[0088] A dispersed phase component solution including: stearic acid
monoglyceride (Kao Corporation, product name: Reodol MS-60, OV=564,
IV=244, IOB value=0.43, HLB value=4.3) as a solid fat of an oil
component; and diethylamino hydroxybenzoyl hexyl benzoate (BASF
Japan Ltd., product name: Uvinul Aplus, OV=480, IV=325, IOB
value=0.68, HLB value=6.77) as a crystalline organic UV absorber
was prepared. In this preparation, the content of stearic acid
monoglyceride and diethylamino hydroxybenzoyl hexyl benzoate in the
final hydrogel particles were 13.5 mass % and 13.5 mass %,
respectively. The contents of stearic acid monoglyceride and
diethylamino hydroxybenzoyl hexyl benzoate in the dispersed phase
component solution were 50 mass % and 50 mass %, respectively. That
is, the content ratio of the crystalline organic UV absorber to the
solid fat was 1 (one). Reodol MS-60 produced by Kao Corporation is
a solid fat containing stearic acid monoglyceride as a main
component.
[0089] A continuous phase component solution including: agar (Ina
Food Industry Co., Ltd., product name: AX-200) as a gel-forming
agent; acrylate-alkyl methacrylate copolymer (Nikko Chemicals Co.,
Ltd., product name: PEMULEN TR-2) and polyvinyl alcohol (Nippon
Synthetic Chemical Industry Co., Ltd., product name: GOHSENOLE
G-05) as emulsifying/dispersing agents; a 1N-NaOH aqueous solution
(KISHIDA CHEMICAL Co., Ltd.) as a pH adjuster; and ion-exchanged
water was prepared. In this preparation, the contents of the above
components in the final hydrogel particles were as follows: agar
was 2.0 mass %; acrylate-alkyl methacrylate copolymer was 0.1 mass
%; polyvinyl alcohol was 0.5 mass %; the 1N-NaOHaqueous solution
was 0.75 mass %; and the balance was ion-exchanged water.
[0090] The dispersed phase component solution and the continuous
phase component solution were prepared in a total amount of 1000 g
such that the mass ratio thereof was 27:73. Then, the dispersed
phase component solution and the continuous phase component
solution were melted by heating at 80.degree. C. and 90.degree. C.,
respectively. Thereafter, the dispersed phase component solution
was added to the continuous phase component solution, and the
resultant mixture was stirred with a homomixer (PRIMIX Corporation,
product name: T. K. Robomix) at a rotation speed of 8000 rpm for
one minute, thereby preparing an oil-in-water dispersion.
[0091] This oil-in-water dispersion was sprayed through a spray
nozzle (IKEUCHI Co., Ltd., hollow cone spray nozzle K-010) at a
flow rate of 12 kg/hr into a gas phase at 25.degree. C. in a tank
at a height of 3.4 m, with the temperature of the oil-in-water
dispersion being kept at 80.degree. C. Then, at the bottom of the
tank, droplets of the oil-in-water dispersion formed by spraying
and solidified by cooling were collected as hydrogel particles of
Example 1.
Example 2
[0092] Hydrogel particles of Example 2 having the same composition
as those of Example 1 except for using propylene glycol
monostearate (Taiyo Kagaku Co., Ltd., product name: Sun Soft No.
25, CD, OV=420, IV=160, IOB value=0.38, HLB value=3.8) as the solid
fat of the oil component, were formed.
Example 3
[0093] Hydrogel particles of Example 3 having the same composition
as those of Example 1 except for using propylene glycol
monobehenate (Riken Vitamin Co., Ltd., product name: Rikemal
PB-100, OV=500, IV=160, IOB value=0.32, HLB value=3.2) as the solid
fat of the oil component, were formed.
Example 4
[0094] Hydrogel particles of Example 4 having the same composition
as those of Example 1 except for the following aspects were formed.
The hydrogel particles of Example 4 used stearic acid monoglyceride
succinate (Kao Corporation, product name: Step SS, OV=500, IV=380,
IOB value=0.76, HLB value=7.6) together with stearic acid
monoglyceride as the solid fat of the oil component in such a
manner that the contents of stearic acid monoglyceride and stearic
acid monoglyceride succinate in the final hydrogel particles were
10.5 mass % and 3.0 mass %, respectively.
[0095] The contents of stearic acid monoglyceride, stearic acid
monoglyceride succinate, and diethylamino hydroxybenzoyl hexyl
benzoate in the dispersed phase component solution were 38.9 mass
%, 11.1 mass %, and 50 mass %, respectively. That is, the content
ratio of the crystalline organic UV absorber to the solid fat was 1
(one).
Example 5
[0096] Hydrogel particles of Example 5 having the same composition
as those of Example 1 except for the following aspects were formed.
The hydrogel particles of Example 5 used stearic acid monoglyceride
as the solid fat of the oil component and also used octyl p-methoxy
cinnamate (BASF Japan Ltd., product name: Uvinul MC80) as liquid
oil in such a manner that the contents of stearic acid
monoglyceride and octyl p-methoxy cinnamate in the final hydrogel
particles were 9.0 mass % and 4.5 mass %, respectively.
[0097] The contents of stearic acid monoglyceride, octyl p-methoxy
cinnamate, and diethylamino hydroxybenzoyl hexyl benzoate in the
dispersed phase component solution were 33.3 mass %, 16.7 mass %,
and 50 mass %, respectively. That is, the content ratio of the
crystalline organic UV absorber to the solid fat was 1.5.
Example 6
[0098] Hydrogel particles of Example 6 having the same composition
as those of Example 1 except that the content of stearic acid
monoglyceride and diethylamino hydroxybenzoyl hexyl benzoate in the
final hydrogel particles were 10.8 mass % and 16.2 mass %,
respectively, were formed. The contents of stearic acid
monoglyceride and diethylamino hydroxybenzoyl hexyl benzoate in the
dispersed phase component solution were 40 mass % and 60 mass %,
respectively. That is, the content ratio of the crystalline organic
UV absorber to the solid fat was 1.5.
Comparative Example 1
[0099] Hydrogel particles of Comparative Example 1 having the same
composition as those of Example 1 except for using behenyl alcohol
(Kao Corporation, product name: Kalcol 220-80, OV=440, IV=100, IOB
value=0.23, HLB value=2.3) as a solid fat, were formed.
Comparative Example 2
[0100] Hydrogel particles of Comparative Example 2 having the same
composition as those of Example 1 except for the following aspects
were formed. The hydrogel particles of Comparative Example 2 used
lauric acid monoglyceride (Taiyo Kagaku Co., Ltd., product name:
Sun Soft No.750, OV=300, IV=260, IOB value=0.87, HLB value=8.7) as
a solid fat in such a manner that the contents of lauric acid
monoglyceride and diethylamino hydroxybenzoyl hexyl benzoate in the
final hydrogel particles were 21.6 mass % and 5.4 mass %,
respectively.
[0101] The contents of lauric acid monoglyceride and diethylamino
hydroxybenzoyl hexyl benzoate in the dispersed phase component
solution were 80 mass % and 20 mass %, respectively. That is, the
content ratio of the crystalline organic UV absorber to the solid
fat was 0.25.
Comparative Example 3
[0102] Hydrogel particles of Comparative Example 3 having the same
composition as those of Comparative Example 2 except for using
ethylene glycol distearate (TOHO Chemical Industry Co., Ltd.,
product name: Pegnol EDS, OV=760, IV=120, IOB value=0.16, HLB
value=1.6) as a solid fat, were formed.
Comparative Example 4
[0103] Hydrogel particles of Comparative Example 4 having the same
composition as those of Example 1 except that the contents of
stearic acid monoglyceride and diethylamino hydroxybenzoyl hexyl
benzoate in the final hydrogel particles were 5.4 mass % and 21.6
mass %, respectively, were formed. The contents of stearic acid
monoglyceride and diethylamino hydroxybenzoyl hexyl benzoate in the
dispersed phase component solution were 20 mass % and 80 mass %,
respectively. That is, the content ratio of the crystalline organic
UV absorber to the solid fat was 4.
TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 Com- Dispersed solid fat
stearic acid monoglyceride 13.5 10.5 9.0 position phase Kao
Corporation/Reodol MS-60 of OV = 564, IV = 244, IOB hydrogel value
= 0.43, HLB value = 4.3 particles propylene glycol monostearate
13.5 mass % Taiyo Kagaku Co., Ltd./Sun Soft No. 25CD OV = 420, IV =
160, IOB value = 0.38, HLB value = 3.8 propylene glycol
monobehenate 13.5 Riken Vitamin Co., Ltd./Rikemal PB-100 OV = 500,
IV = 160, IOB value = 0.32, HLB value = 3.2 stearic acid
monoglyceride succinate 3.0 Kao Corporation/Step SS OV = 500, IV =
380, IOB value = 0.76, HLB value = 7.6 behenyl alcohol Kao
Corporation/KALCOL220-80 OV = 440, IV = 100, IOB value = 0.23, HLB
value = 2.3 lauric acid monoglyceride Taiyo Kagaku Co., Ltd./Sun
Soft No. 750 OV = 300, IV = 260, IOB value = 0.87, HLB value = 8.7
ethylene glycol distearate TOHO Chemical Industry Co., Ltd./Pegnol
EDS OV = 760, IV = 120, IOB value = 0.16, HLB value = 1.6 liquid
oil octyl p-methoxy cinnamate 4.5 BASF Japan Ltd./Uvinul MC80
crystalline diethylamino hydroxybenzoyl hexyl benzoate 13.5 13.5
13.5 13.5 13.5 organic BASF Japan Ltd./Uvinul Aplus UV absorber OV
= 480, IV = 325, IOB value = 0.68, HLB value = 6.77 Continuous
gel-forming agar 2.0 2.0 2.0 2.0 2.0 phase agent Ina Food Industry
Co., Ltd./AX-200 emulsifying/ acrylate-alkyl methacrylate copolymer
0.1 0.1 0.1 0.1 0.1 dispersing Nikko Chemicals Co., Ltd./PEMULEN
TR-2 agent polyvinyl alcohol 0.5 0.5 0.5 0.5 0.5 The Nippon
Synthetic Chemical Industry Co., Ltd./GOHSENOLE G-05 pH adjuster 1N
NaOH 0.75 0.75 0.75 0.75 0.75 KISHIDA CHEMICAL Co., Ltd.
ion-exchanged water balance balance balance balance balance Content
of crystalline organic UV 50 50 50 50 50 absorber in dispersed
phase (mass %) Volume-based average particle 150 150 150 150 150
size of hydrogel particles (.mu.m) Storage stability Presence of
crystal precipitation No No No No No evaluation after 2-week
storage at room temperature Presence of crystal precipitation No No
No -- -- after 2-week storage in 5.degree. C. atmosphere Presence
of crystal precipitation No No No -- -- after 2-week storage in
40.degree. C. atmosphere Exam- Comparative ple Example 6 1 2 3 4
Com- Dispersed solid fat stearic acid monoglyceride 10.8 5.4
position phase Kao Corporation/Reodol MS-60 of OV = 564, IV = 244,
IOB hydrogel value = 0.43, HLB value = 4.3 particles propylene
glycol monostearate mass % Taiyo Kagaku Co., Ltd./Sun Soft No. 25CD
OV = 420, IV = 160, IOB value = 0.38, HLB value = 3.8 propylene
glycol monobehenate Riken Vitamin Co., Ltd./Rikemal PB-100 OV =
500, IV = 160, IOB value = 0.32, HLB value = 3.2 stearic acid
monoglyceride succinate Kao Corporation/Step SS OV = 500, IV = 380,
IOB value = 0.76, HLB value = 7.6 behenyl alcohol 13.5 Kao
Corporation/KALCOL220-80 OV = 440, IV = 100, IOB value = 0.23, HLB
value = 2.3 lauric acid monoglyceride 21.6 Taiyo Kagaku Co.,
Ltd./Sun Soft No. 750 OV = 300, IV = 260, IOB value = 0.87, HLB
value = 8.7 ethylene glycol distearate 21.6 TOHO Chemical Industry
Co., Ltd./Pegnol EDS OV = 760, IV = 120, IOB value = 0.16, HLB
value = 1.6 liquid oil octyl p-methoxy cinnamate BASF Japan
Ltd./Uvinul MC80 crystalline diethylamino hydroxybenzoyl hexyl
benzoate 16.2 13.5 5.4 5.4 21.6 organic BASF Japan Ltd./Uvinul
Aplus UV absorber OV = 480, IV = 325, IOB value = 0.68, HLB value =
6.77 Continuous gel-forming agar 2.0 2.0 2.0 2.0 2.0 phase agent
Ina Food Industry Co., Ltd./AX-200 emulsifying/ acrylate-alkyl
methacrylate copolymer 0.1 0.1 0.1 0.1 0.1 dispersing Nikko
Chemicals Co., Ltd./PEMULEN TR-2 agent polyvinyl alcohol 0.5 0.5
0.5 0.5 0.5 The Nippon Synthetic Chemical Industry Co.,
Ltd./GOHSENOLE G-05 pH adjuster 1N NaOH 0.75 0.75 0.75 0.75 0.75
KISHIDA CHEMICAL Co., Ltd. ion-exchanged water balance balance
balance balance balance Content of crystalline organic UV 60 50 20
20 80 absorber in dispersed phase (mass %) Volume-based average
particle 176 150 150 150 161 size of hydrogel particles (.mu.m)
Storage stability Presence of crystal precipitation No Yes Yes Yes
Yes evaluation after 2-week storage at room temperature Presence of
crystal precipitation No -- -- -- No after 2-week storage in
5.degree. C. atmosphere Presence of crystal precipitation No Yes --
-- No after 2-week storage in 40.degree. C. atmosphere
Example 7
[0104] Hydrogel particles of Example 7 having the same composition
as those of Example 1 except for the following aspects were formed.
The hydrogel particles of Example 7 used dimethoxybenzylidene
dioxoimidazolidine propionate octyl (Ajinomoto Co., Inc., product
name: Soft Shade DH, OV=460, IV=462, IOB value=1.00, HLB
value=10.04) as a crystalline organic UV absorber in such a manner
that the contents of stearic acid monoglyceride and
dimethoxybenzylidene dioxoimidazolidine propionate octyl in the
final hydrogel particles were 21.6 mass % and 5.4 mass %,
respectively.
[0105] The contents of stearic acid monoglyceride and
dimethoxybenzylidene dioxoimidazolidine propionate octyl in the
dispersed phase component solution were 80 mass % and 20 mass %,
respectively. That is, the content ratio of the crystalline organic
UV absorber to the solid fat was 0.25.
Example 8
[0106] Hydrogel particles of Example 8 having the same composition
as those of Example 6 except for using propylene glycol
monostearate as a solid fat, were formed.
Example 9
[0107] Hydrogel particles of Example 9 having the same composition
as those of Example 6 except for using propylene glycol
monobehenate as a solid fat, were formed.
Comparative Example 5
[0108] Hydrogel particles of Comparative Example 5 having the same
composition as those of Example 7 except for using lauric acid
monoglyceride as a solid fat, were formed.
Reference Example
[0109] For preparation, behenyl alcohol is used as a solid fat, and
the contents of behenyl alcohol and dimethoxybenzylidene
dioxoimidazolidine propionate octyl in the final hydrogel particles
were 21.6 mass % and 5.4 mass %, respectively. However, these
components were not dissolved in each other. Thus, no dispersed
phase component solution was prepared.
TABLE-US-00002 TABLE 2 Comparative Example Example 7 8 9 5
Composition Dispersed solid fat stearic acid monoglyceride 21.6 of
hydrogel phase Kao Corporation/Reodol MS-60 particles OV = 564, IV
= 244, IOB value = 0.43, HLB mass % value = 4.3 propylene glycol
monostearate 21.6 Taiyo Kagaku Co., Ltd./Sun Soft No. 25CD OV =
420, IV = 160, IOB value = 0.38, HLB value = 3.8 propylene glycol
monobehenate 21.6 Riken Vitamin Co., Ltd./Rikemal PB-100 OV = 500,
IV = 160, IOB value = 0.32, HLB value = 3.2 lauric acid
monoglyceride 21.6 Taiyo Kagaku Co., Ltd./Sun Soft No. 750 OV =
300, IV = 260, IOB value = 0.87, HLB value = 8.7 crystalline
dimethoxybenzylidene dioxoimidazolidine 5.4 5.4 5.4 5.4 organic
propionate octyl UV Ajinomoto Co., Inc./Soft Shade DH absorber OV =
460, IV = 462, IOB value = 1.00, HLB value = 10.04 Continuous
gel-forming agar 2.0 2.0 2.0 2.0 phase agent Ina Food Industry Co.,
Ltd./AX-200 emulsifying/ acrylate-alkyl methacrylate copolymer 0.1
0.1 0.1 0.1 dispersing Nikko Chemicals Co., Ltd./PEMULEN TR-2 agent
polyvinyl alcohol 0.5 0.5 0.5 0.5 The Nippon Synthetic Chemical
Industry Co., Ltd./GOHSENOLE G-05 pH adjuster 1N NaOH 0.75 0.75
0.75 0.75 KISHIDA CHEMICAL Co., Ltd. ion-exchanged water balance
balance balance balance Content of crystalline organic UV absorber
in dispersed phase (mass %) 20 20 20 20 Volume-based average
particle size of hydrogel particles (.mu.m) 150 150 150 150 Storage
stability Presence of crystal precipitation after 2-week No No No
Yes evaluation storage at room temperature Presence of crystal
precipitation after 2-week -- No No -- storage in 5.degree. C.
atmosphere Presence of crystal precipitation after 2-week -- No No
-- storage in 40.degree. C. atmosphere
Test Evaluation Method
Volume-Based Average Particle Size
[0110] Median particle sizes of the hydrogel particles of Examples
1-9 and Comparative Examples 1-5 were measured with a laser
diffraction/scattering particle size distribution analyzer (HORIBA,
Ltd., product number: LA-920), and the obtained median particle
sizes were used as volume-based average particle sizes of the
hydrogel particles.
Storage Stability Evaluation
[0111] For the hydrogel particles of each of Examples 1-9 and
Comparative Examples 1-5, slurry having a composition in which the
content of the hydrogel particles was 50 mass %, the content of
phenoxyethanol (TOHO Chemical Industry Co., Ltd., product name:
High-solve EPH) was 0.2 mass %, the content of ethanol was 8.31
mass %, and the content of purified water was 41.49 mass % as shown
in Table 3 was prepared.
TABLE-US-00003 TABLE 3 Slurry composition hydrogel particles 50
mass % phenoxyethanol 0.2 TOHO Chemical Industry Co., Ltd./
High-solve EPH ethanol 8.31 purified water 41.49
[0112] After the slurry has been stored for 2 weeks at room
temperature, the state of the dispersed phase in the hydrogel
particles was observed with a CCD (KEYENCE, product name: DIGITAL
MICROSCOPE VHX-500) to detect the presence/absence of crystal
precipitation of the crystalline organic UV absorber. The state in
which the crystalline organic UV absorber grew to be coarse needle
crystal with a size of 50 .mu.m or more in the dispersed phase is
defined as the presence (Yes) of crystal precipitation, whereas the
state in which no such growth was observed is defined as the
absence (No) of crystal precipitation.
[0113] A test evaluation similar to the case of storage for 2 weeks
in a 5.degree. C. atmosphere was conducted on the hydrogel
particles of Examples 1-3, 6, 8, and 9, and Comparative Example 4.
A test evaluation similar to the case of storage for 2 weeks in a
40.degree. C. atmosphere was conducted on the hydrogel particles of
Examples 1-3, 6, 8, and 9, and Comparative Examples 1 and 4.
Test Evaluation Results
[0114] Test evaluation results are shown in Tables 1 and 2.
[0115] With respect to the volume-based average particle size,
Examples 1-5 and 7-9 and Comparative Examples 1-3 and 5 were 150
.mu.m, Example 6 was 176 .mu.m, and Comparative Example 4 was 161
.mu.m.
[0116] With respect to the storage stability evaluation at room
temperature, Examples 1-9 showed the absence (No) of crystal
precipitation, whereas Comparative Examples 1-5 showed the presence
(Yes) of crystal precipitation.
[0117] With respect to the storage stability evaluation in a
5.degree. C. atmosphere, Examples 1-3, 6, 8, and 9, and Comparative
Example 4 showed the absence (No) of crystal precipitation.
[0118] With respect to the storage stability evaluation in a
40.degree. C. atmosphere, Examples 1-3, 6, 8, and 9, and
Comparative Example 4 showed the absence (No) of crystal
precipitation, whereas Comparative Example 1 showed the presence
(Yes) of crystal precipitation.
Test Evaluation 2
UV-Shielding Cosmetic Product
Example 10
[0119] For the hydrogel particles of Example 1, slurry with a
composition in which the content of hydrogel particles was 50 mass
%, the content of phenoxyethanol (TOHO Chemical Industry Co., Ltd.,
product name: High-solve EPH) was 0.2 mass %, the content of
ethanol was 10.00 mass %, and the content of purified water was
39.8 mass %, was prepared. To examine applicability of this slurry
to UV-shielding cosmetic products, cosmetic base materials
described in Table 4 were added to prepare an UV-shielding cosmetic
product of Example 10.
[0120] Specific composition was as follows: hydrogel particle
slurry was 20 mass %; 2-ethylhexyl p-methoxy cinnamate (BASF
Corporation, product name: Uvinul MC80) was 8.5 mass %; dimeticone
(Shin-Etsu Chemical Co., Ltd., product name: Silicone KF-96A
(10cs)) was 1.0 mass %; acrylic acid copolymer (Nikko Chemicals
Co., Ltd., product name: Carbopol ETD2020) was 0.1 mass %;
acrylate-alkyl methacrylate copolymer (Nikko Chemicals Co., Ltd.,
product name: PEMULEN TR-2) was 0.2 mass %; acrylate-alkyl
methacrylate copolymer (Nikko Chemicals Co., Ltd., product name:
PEMULEN TR-1) was 0.2 mass %; phenoxyethanol (TOHO Chemical
Industry Co., Ltd., product name: High-solve EPH) was 0.4 mass %;
liquid caustic potash (48%) was 0.36 mass %; ethanol was 10 mass %;
and the balance was purified water.
Comparative Example 6
[0121] Cosmetic base materials described in Table 4 were mixed to
prepare an UV-shielding cosmetic product of Comparative Example
6.
[0122] Specifically, in Comparative Example 6, the composition was
as follows: 2-ethylhexyl p-methoxy cinnamate (BASF Corporation,
product name: Uvinul MC80) was 8.5 mass %; dimeticone (Shin-Etsu
Chemical Co., Ltd., product name: Silicone KF-96A (10cs)) was 1.0
mass %; diethylamino hydroxybenzoyl hexyl benzoate (BASF
Corporation, product name: Uvinul Aplus) was 1.35 mass %; glyceryl
stearte (Kao Corporation, product name: Reodol MS-60) was 1.35 mass
%; acrylic acid copolymer (Nikko Chemicals Co., Ltd., product name:
Carbopol ETD2020) was 0.1 mass %; acrylate-alkyl methacrylate
copolymer (Nikko Chemicals Co., Ltd., product name: PEMULEN TR-2)
was 0.2 mass %; acrylate-alkyl methacrylate copolymer (Nikko
Chemicals Co., Ltd., product name: PEMULEN TR-1) was 0.2 mass %;
phenoxyethanol (TOHO Chemical Industry Co., Ltd., product name:
High-solve EPH) was 0.4 mass %; liquid caustic potash (48%) was
0.36 mass %; ethanol was 10 mass %; and the balance was purified
water.
TABLE-US-00004 TABLE 4 Example Comparative 10 Example 6 hydrogel
particle slurry 20 0 2-ethylhexyl p-methoxy cinnamate BASF
Corporation 8.5 8.5 product name: Uvinul MC80 dimeticone 1.0 1.0
Shin-Etsu Chemical Co., Ltd. product name: Silicone KF-96A (10cs)
diethylamino hydroxybenzoyl hexyl benzoate 1.35 BASF Corporation
product name: Uvinul Aplus glyceryl stearte 1.35 Kao Corporation,
product name: Reodol MS-60 acrylic acid copolymer 0.1 0.1 Nikko
Chemicals Co., Ltd. product name. Carbopol ETD2020 acrylate-alkyl
methacrylate copolymer 0.2 0.2 Nikko Chemicals Co., Ltd. product
name: PEMULEN TR-2 acrylate-alkyl methacrylate copolymer 0.2 0.2
Nikko Chemicals Co., Ltd. product name: PEMULEN TR-1 phenoxyethanol
0.4 0.4 TOHO Chemical Industry Co., Ltd. product name: High-solve
EPH liquid caustic potash (48%) 0.36 0.36 ethanol 10 10 purified
water balance balance Feeling 4.3 4.3 Storage stability (50.degree.
C., one month) A C Separation confirmation test (200-mL beaker, A C
rotation speed: 10 rpm, stirring for 60 minutes)
Test Evaluation Method
Actual Use Test
[0123] UV-shielding cosmetic products including the hydrogel
particles of Example 10 and
[0124] Comparative Example 6 were applied forearms of three expert
panelists, and an actual use test on moistness of the skin was
conducted. Then, the average scores of the three panelists were
obtained based on the following criteria.
Criteria
[0125] Score 5: moist
[0126] Score 4: slightly moist
[0127] Score 3: neither
[0128] Score 2: slightly not moist
[0129] Score 1: not moist
Storage Stability Test
[0130] The UV-shielding cosmetic products including the hydrogel
particles of Example 10 and Comparative Example 6 were allowed to
stand and, after one-month storage in a 50.degree. C. atmosphere,
the presence/absence of separation was visually inspected, thus
performing evaluation based on the following criteria.
Separation Inspection Test
[0131] In this test, 200 mL of each of the UV-shielding cosmetic
products including the hydrogel particles of Example 10 and
Comparative Example 6 was placed in a 200-mL beaker, and after
60-minutes stirring with an agitator at a rotation speed of 10 rpm,
the presence/absence of separation was visually inspected, thus
performing evaluation based on the following criteria.
[0132] A: no separation
[0133] B: slightly separated
[0134] C: separated
Test Evaluation Results
[0135] Table 4 shows test evaluation results.
[0136] With respect to the average score of the feel in the actual
use test, Example 10 showed 4.3 and Comparative Example 6 showed
4.3.
[0137] With respect to the storage stability after one month at
50.degree. C., Example 10 showed A and Comparative Example 6 showed
C.
[0138] With respect to the presence/absence in the separation
inspection test, Example 10 showed A and Comparative Example 6
showed C.
INDUSTRIAL APPLICABILITY
[0139] The present disclosure is useful for hydrogel particles and
methods for producing hydrogel particles.
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